Pfizer shareholders are having a good year. The stock is up 23 per cent in 2021, with much of those gains coming in recent weeks on foot of continued demand for its Covid-19 vaccine.

If you're a long-term investor, however, holding Pfizer has been a testing affair. The stock remains just below all-time highs set all the way back in April 1999, notes Bespoke Investment, making it one of the few blue chips still below its 1990s peak.

That said, reliable dividends have cushioned the blow for Pfizer shareholders. Although the stock remains below 1999 levels, it has actually returned 103 per cent over that time frame, if one includes dividends.

The impact of dividends is even more dramatic if one goes further back again, to 1990. The stock’s total annualised return has been 12.5 per cent, compared with 9.2 per cent excluding dividends. An insignificant difference? It’s not – excluding dividends, Pfizer is up 1,523 per cent, says Bespoke, compared with a whopping 4,075 per cent if dividends are included.

That’s the magic of compound interest. Small sums snowball over time; mighty oaks from little acorns grow.